Sandwich panel including honeycomb structure body and method of producing the sandwich panel

A method of producing a honeycomb structure body consisting of a piece of honeycomb (2) and a phenol resin foam (1) inserted in cell spaces of the honeycomb, the foam having a linked cellular structure, wherein the size in height and width of the sheet-like foam before insertion is greater than the size of the honeycomb, so that the honeycomb is surrounded by the edges of the sheet-like foam, the method comprising steps of:

• applying a liquid adhesive agent (7) exhibiting a prescribed value of viscosity to the tips of cell walls in narrow belt-like areas on one side of the honeycomb,
• pressing a permeable surface material (8) onto the side of the honeycomb to which the adhesive agent has been applied,
• inserting a water-absorbent foam (1) into the cell spaces of the honeycomb from the other side thereof, until the foam comes in contact with the adhesive agent that has been applied,
• wherein hardening of the adhesive agent is accelerated because water in the adhesive agent is absorbed by the water-absorbent foam.